5-74685274-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000521.4(HEXB):c.14G>A(p.Gly5Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000937 in 1,388,096 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (no stars). Synonymous variant affecting the same amino acid position (i.e. G5G) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000094 (0 hom.)
• Consequence: HEXB NM_000521.4 missense
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: -0.0440

Genes affected

HEXB (HGNC:4879): (hexosaminidase subunit beta) Hexosaminidase B is the beta subunit of the lysosomal enzyme beta-hexosaminidase that, together with the cofactor GM2 activator protein, catalyzes the degradation of the ganglioside GM2, and other molecules containing terminal N-acetyl hexosamines. Beta-hexosaminidase is composed of two subunits, alpha and beta, which are encoded by separate genes. Both beta-hexosaminidase alpha and beta subunits are members of family 20 of glycosyl hydrolases. Mutations in the alpha or beta subunit genes lead to an accumulation of GM2 ganglioside in neurons and neurodegenerative disorders termed the GM2 gangliosidoses. Beta subunit gene mutations lead to Sandhoff disease (GM2-gangliosidosis type II). Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.11458337).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HEXB	NM_000521.4	c.14G>A	p.Gly5Glu	missense_variant	1/14	ENST00000261416.12
HEXB	NM_001292004.2	c.-376-4054G>A		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HEXB	ENST00000261416.12	c.14G>A	p.Gly5Glu	missense_variant	1/14	1	NM_000521.4	P1
HEXB	ENST00000511181.5	c.-376-4054G>A		intron_variant		1
HEXB	ENST00000513079.5	n.79G>A		non_coding_transcript_exon_variant	1/6	2
HEXB	ENST00000515528.1	n.69G>A		non_coding_transcript_exon_variant	1/2	2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000719 AC: 1 AN: 139060 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 76522

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000186

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000937 AC: 13 AN: 1388096 Hom.: 0 Cov.: 30 AF XY: 0.0000131 AC XY: 9 AN XY: 685594

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000120

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: no assertion criteria provided

Submissions by phenotype

Sandhoff disease Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Natera, Inc.

Aug 15, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Uncertain	0.042	T
BayesDel_noAF	Benign	-0.18
Cadd	Benign	18
Dann	Benign	0.97
Eigen	Benign	-1.0
Eigen_PC	Benign	-1.0
FATHMM_MKL	Benign	0.0075	N
M_CAP	Uncertain	0.21	D
MetaRNN	Benign	0.11	T
MetaSVM	Uncertain	-0.0089	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	-0.69	N
REVEL	Benign	0.18
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Vest4		0.20
MutPred		0.39		Loss of sheet (P = 0.0181);
MVP		0.76
MPC		0.23
ClinPred		0.12	T
GERP RS		-0.24
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
gMVP		0.50

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1400667054; hg19: chr5-73981099;